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spkrman15
11-01-2001, 11:25 PM
Well i am having some problems getting my lathe to cut a straight. I figured it might be my tail stock. I was woundering if anyone could give me a tip on how to verify my tailstock is on center.

Thanks spkrman

Thrud
11-02-2001, 12:20 AM
Put a good set of centers in both headstock & tailstock. Move tailstock towards headstock , the tips should align dead on after clamping the tailstock to the bed. If not adjust the tailstock centering screws until aligned.

To align more accurately turn a test bar and adjust until both ends measure equally.

Dave

SGW
11-02-2001, 06:59 AM
See the "Squaring a Lathe" thread further down in this forum, especially the link to http://people.ne.mediaone.net/wasser/NEMES/RDMLatheAlignment.html

For checking your tailstock, I'd put an indicator in the headstock and run it around the inside of the tailstock socket, or around the outside of a center in the tailstock, or similar. You'll have to stand on your head a bit to read the indicator as it goes around, but it will tell you, for sure.

I think turning a test bar between centers may fool you, as the problem may not be your tailstock at all -- your lathe bed may be twisted.

spkrman15
11-02-2001, 04:06 PM
thanks guys. I have been giving the lathe bed leveling a try. I am having problems reaching one of my ancor bolt holes. I am having a difficult time getting things centered in my self centering jaw. I am not dismissing the fact that it might be me. I am on holidays for the next little while so i will be able to be a little more patient. Wish me luck

Spkr

JIM DEWOLF
11-02-2001, 11:10 PM
I agree with SEW. Dial off your spindle as explained. Rather than to break your neck, just use a mirror to see dial when it's under.
Can one of you tell me, if you have a shaft acuratly centered both ends and same size both ends, set up between centres, say full length of lathe minus tail stock of course, would this not be a good way to level or to check the level of the lathe. The tail stock would have to be dialed per SEW's instructions. Would this tell you if the bed is twisted? Am I making any sense?
Your comments please.
Jim

Jim Hubbell
11-03-2001, 01:42 AM
A test bar between centers alignes the tailstock so that ways are parallel with the test bar. This says nothing about spindle center line. Correct me if I am wrong.
Jim Hubbell

SGW
11-03-2001, 07:05 AM
Right - the instructions on that web page assume the test bar is being held by the headstock only (chuck or collet). By doing the procedure described, you align the ways with the spindle centerline.

Putting a test bar between centers, on the other hand, tells you nothing about the spindle centerline. It would be quite possible to have some twist in the lathe bed, some setover of the tailstock, have them cancel out, and presto! you'd think everything was fine. Then you'd put a piece in your 3-jaw chuck, turn it down, find out you're turning a taper, and wonder why.

IF you've aligned the headstock first (as per that web page), then a test bar between centers is a way of aligning the tailstock. But you need the spindle centerline aligned with the ways first.

spkrman15
11-03-2001, 08:23 AM
SGW that is exactly what i did. I got the spindle aligned then adjusted my headstock. Voila. Now i am getting under .001 deviation. There may be some more fine tunning to do but i figured i would see after i did a little work. See how things make out. IT might be flexing of the bar as i turn it down. I shall see

Spkrman